1. Field of the Invention
The present invention relates to a method of manufacturing an ejection orifice member, which is a member for forming a liquid droplet ejection head such as an inkjet recording head, and which has an ejection orifice for ejecting a liquid droplet formed therein. It is to be noted that the term “ejection orifice” herein employed means an entire through hole passing through the ejection orifice member in a thickness direction, including an opening defined in a surface of the ejection orifice member as an end portion of the through hole.
2. Description of the Related Art
In an inkjet recording head, it is desired that a droplet of liquid such as ink be ejected with a small drive force. In order to reduce the drive force, it is effective to reduce fluid resistance through an ejection orifice of an ejection orifice member. One way to accomplish this is to reduce the length of the ejection orifice. However, if the entire ejection orifice member is thinned, strength of the ejection orifice member is reduced, and not only handling of the ejection orifice member becomes difficult but also the ejection orifice member becomes more liable to break. Another way to accomplish this is to taper the ejection orifice. However, if the ejection orifice includes only a tapered portion, from the viewpoint of the manufacturing method, it is difficult to control the accuracy of the diameter of the ejection orifice which is an opening of the ejection orifice on an ejection side. Further, from the viewpoint of usage, the ejection orifice portion is liable to be deformed and damaged.
Therefore, as a structure of an ejection orifice having a reduced fluid resistance and having accurately controlled dimensions, it is desired that one end side of the ejection orifice communicating to an ink flow path be tapered and the other end side thereof as an ink ejection side be in a short and straight shape.
As such a technology, in Japanese Patent Application Laid-Open No. 2004-330636, there is disclosed a method of manufacturing an ejection orifice member having an ejection orifice which includes a tapered portion and a straight portion. The manufacturing method includes forming the tapered portion of the ejection orifice by proximity exposure and plating and forming the straight portion of the ejection orifice by exposure and plating from a rear surface of a transparent substrate.